ValueClick Inc. on Monday said that it had acquired mobile advertising network Greystripe Inc. for about $70 million in cash.

Greystripe’s advertising platform is used by companies to direct ads to more than 30 million users of cell phones and other mobile devices. Westlake Village-based ValueClick, which provides online advertising campaigns and related services, said Greystripe provides it with scale in the estimated $1.1 billion mobile advertising market in the United States. That market is expected to nearly double by 2013.

Greystripe is expected to contribute about $24 million to ValueClick’s adjusted consolidated operating income this year and be accretive to earnings in 2012. Greystripe becomes a wholly-owned unit of the ValueClick Media division, and its management team and employees have been retained.

“We see great traffic and revenue synergies between ValueClick and Greystripe,” said Chief Executive Jim Zarley in a statement.

ValueClick also announced preliminary results for the first quarter. The company said it had revenue of $117 million and adjusted-EBITDA of $35.1 million, which exceeded the high-end of the guidance ranges management provided on Feb 15. In addition, ValueClick repurchased around 2.2 million common shares in the first quarter and about 400,000 million more shares this month, for a total cost of $37.7 million.

Shares were up 28 cents, or 1.8 percent, to $16.07 in midday trading on the Nasdaq.