German insurance giant Allianz said that it was keeping its options open on a possible increase in its takeover offer for British construction group John Laing after rival bidder, asset management group Henderson, upped its price.

"We're examining our options," an Allianz spokeswoman said Friday, refusing to elaborate further.

Earlier, Henderson had announced it was raising its bid for John Laing to 405 pence per share (6.02 euros, 7.67 dollars) per share, outbidding Allianz's offer of 385 pence per share.

Henderson's new offer values John Laing at a total 1.004 billion pounds, compared Allianz's bid which is worth a total 957.5 million pounds.

John Laing, which specialises in the construction of hospitals and schools, had withdrawn its recommendation of the earlier Henderson offer and had recommended its shareholders to accept the Allianz offer instead.