Court documents show that Sebastian Marineau-Mes wanted to join Apple in March as head of Core OS team, but has been put on 'vacation pay' until June

BlackBerry sued one of its executives who is leaving to join Apple, tying him to the company until June, a court judgment filed in Ontario shows.

Sebastien Marineau-Mes, the senior vice-president for software at the struggling Canadian handset and software company, had been in talks to leave the company since September 2013, and Apple offered him the job of "vice president of Core OS" – believed to be for its iOS mobile software – in December 2013.

But having resigned at the end of December, Marineau-Mes has been told that he must stay until June, because a contract he signed in October promoting him to executive vice-president (EVP) of platform development made it obligatory to give six months' notice of his resignation.

That contract though was signed while the company was going through turmoil in which an expected buyout bid did not materialise – and the company had a freeze on promotions. Marineau-Mes argued in court that that effectively invalidated the promotion, and that his role as EVP had changed with the arrival of new chief executive John Chen in November 2013.

But the court ruled that BlackBerry can hold Marineau-Mes to his contract until 23 June 2014, even though he sought a declaration that the contract is "not valid and enforceable".

Marineau-Mes formerly worked at QNX Software, which BlackBerry bought in autumn 2010, and by last September was running a team of 600 people, with three vice-presidents below him. The promotion to EVP put him in charge of 3,000 people, BlackBerry said.

The judgment sheds light on the unrest inside the company, where a number of high-ranking executives have left following the appointment of Chen, who previously turned around the struggling software company Sybase.

In his submission, Marineau-Mes says that he has in effect not worked for BlackBerry since the beginning of January, when he was put on "vacation pay". But internal emails confirmed that he had been promoted, even though the move wasn't announced because of the promotion freeze then in place. BlackBerry argued that it wanted him to remain "available" - though there was no indication that it would actually call on his services.

BlackBerry said in a statement that "It is unfortunate that we had to take this step, but we will do whatever is necessary to ensure that employees honor the agreements they make with us. " Apple did not respond to a request for comment by publication time.

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