Inmarsat, Britain’s leading satellite company, has rejected a bid approach from a US rival, in what could signal the start of a fresh foreign takeover saga.

Responding to a 13.5% rise in its share price on Friday, Inmarsat admitted it had received an offer from Colorado-based EchoStar that it said “very significantly undervalued” the company and its prospects.

If EchoStar persists, Inmarsat is likely to become the focus of renewed concern about takeovers of leading British businesses, coming shortly after Melrose finally succeeded with its controversial £8bn pursuit of engineer GKN.

Like GKN, Inmarsat, which employs more than 1,500 people, has provided technology used by the British armed forces, although its largest single customer is the US military.

The London-based company, which has 13 communications satellites in orbit, provided satellite services to the Ministry of Defence to improve ground communications for soldiers fighting in Afghanistan.

Its “groundbreaking” technology was used in the hunt for the missing Malaysia Airlines flight 370, which disappeared in 2014 and is believed to have crashed into the southern Indian Ocean.

The firm has repeatedly won praise from the government thanks to its leadership position in the British space industry, excluding the Franco-German industrial group Airbus, which has sizeable operations in the UK but is French-owned.

Former chancellor George Osborne praised Inmarsat in 2012 as he announced £1.2bn of funding over five years to increase Britain’s role in European space projects.

The UK’s place in the European Space Agency, which is working on the €10bn Galileo satellite navigation system, is now uncertain amid the ongoing Brexit negotiations. Inmarsat is also a world leader in several cutting-edge technologies such as mobile satellite communications and maritime and aviation safety, while it is among the largest providers of inflight internet for airlines.

Its four Global Xpress satellites provide the world’s only global high-speed broadband operation, with a fifth satellite due to launch next year to increase capacity. It is also working with Germany’s Deutsche Telekom on the European Aviation Network, which will provide high-speed broadband to air passengers across the continent.

Despite Inmarsat’s leading position in several markets, New York-listed EchoStar is the larger company based on its stock market value of £3.4bn, compared with the UK firm’s £2.2bn after its stock market surge on Friday.

Sign up to the daily Business Today email or follow Guardian Business on Twitter at @BusinessDesk

EchoStar’s interest is likely to be fuelled in part by Inmarsat’s exposure to the US, given that the US military is the company’s largest single customer.

But if the US firm persists with its bid, it could face political opposition similar to that seen during Melrose’s bid for GKN. A group of MPs urged the business secretary, Greg Clark, to block that deal on national security grounds. Security is one of the few reasons the government can prevent a takeover and the MPs cited fears that GKN could be broken up and sold to overseas buyers.

If it is to stave off EchoStar’s interest, Inmarsat’s management – led by chief executive Rupert Pearce – will be reliant on the support of major shareholders, with whom it has been at loggerheads over pay. A revolt from more than 60% of voting investors earlier this year forced Inmarsat to rip up its pay proposals, continuing a long-running dispute that had broken out into rebellion three times in the past six years.

A government spokesperson said: “While no formal bid or offer has been made, we are monitoring the situation. However, this is a commercial matter for the companies involved.”