* Balfour buys part of Rok's housing, construction business
* New businesses to add around 100 mln stg/yr to sales
LONDON, Nov 19 (Reuters) - Balfour Beatty (BALF.L) has bought some of collapsed UK maintenance firm Rok's affordable housing and construction businesses for 7 million pounds, it said on Friday.
Balfour, Britain's market leader in big-ticket construction projects, said the newly acquired businesses and their 381 employees would be folded into Mansell, its regional construction business, and would add around 100 million pounds a year to group sales.
"Rok's operations in affordable housing, which are principally in the South West and North West of the UK, will support Mansell's strategy of being a leading provider in affordable housing where long-term demographics are favourable," Balfour said in a statement.
"Rok's general construction activities will enhance Mansell's existing capabilities at Heathrow and Gatwick airports as well as expanding its geographical presence into the South Midlands."
Rok went into administration earlier this month after difficulties meeting financial obligations, two months after bigger rival Connaught collapsed. [ID:nLDE6A7098]
Balfour, which helped build the world's biggest shopping centre, the Burj Mall in Dubai, said it had paid an initial 4 million pounds and would settle the remianing balalncce once contracts were exchanged.
"We are working with Rok's administrator towards an efficient transition of these operations to minimise disruption to clients and to protect jobs in the operations we are acquiring," Balfour added.
Shares in Balfour Beatty, which have risen 7 percent in the last three months, closed at 279.30 pence on Thursday, valuing the company at around 1.9 billion pounds.
Reporting by Rhys Jones, Editing by Matt Scuffham