WeWork owner The We Company is weighing slashing the valuation of its forthcoming IPO to below $20 billion, two sources said, in the latest headwind for leading shareholder SoftBank, whose key group portfolio firms have tumbled in value.

The valuation for the money-losing office-sharing startup could be as low as $15 billion to $18 billion, one of the sources with direct knowledge of the matter said. The other source said the valuation was unlikely to be as low as that.

SoftBank, whose $100 billion Vision Fund is widely seen as having contributed to frothy tech valuations, has urged WeWork to shelve the IPO due to tepid investor demand, the Financial Times reported. SoftBank declined to comment.

But the tech conglomerate’s reluctance to pump further funds into WeWork means the startup “may have no choice but to push ahead with the IPO at a much-lower-than-anticipated valuation,” one of the sources said.

WeWork’s planned listing follows weak initial trading at other startups including Uber and Slack, both backed by SoftBank.

While SoftBank and its Vision Fund emphasize their long-term investing credentials, founder and CEO Masayoshi Son has set out an ambitious IPO pipeline for tech investments spanning ride-hailing, financial tech and health startups.

Putting WeWork’s offering on hold would disrupt that schedule at a time when SoftBank is seeking funds from investors for a second Vision Fund, for which it says $108 billion in pledges have been secured.

SoftBank made a follow-on investment in WeWork, one of its biggest tech bets, at a $47 billion valuation earlier this year — a number widely treated with skepticism by analysts.

While long-time Son lieutenant and group vice chairman Ron Fisher is pushing for the IPO to go ahead, others at SoftBank are pushing for a delay, one source said.

Sanford C. Bernstein analyst Chris Lane said that if WeWork halts its IPO, SoftBank could come up with an alternative funding plan for the startup, which he estimates needs $9 billion in funding to become cash-flow-positive.

SoftBank “have got an important voice, but more importantly, they have money … (WeWork) will have to listen to them,” said Lane, who values the office space-sharing firm at $23 billion.