Twitter and advertising giant Omnicom Group have agreed to an arrangement where Twitter's MoPub mobile ad exchange will link with Omnicom's automated ad buying unit Accuen.

The two-year deal is valued at $230m (£137m, €169m).

The mobile-focused partnership will lock in ad rates and inventory access for Omnicom agencies and will also give Omnicom a "first look" at new ad units and opportunities being developed by the microblogging site, reported The Wall Street Journal.

"Twitter's been a major advertising partner for our clients in the past...(Omnicom) wanted to form a closer business relationship with Twitter that extends beyond just media buying," Jonathan Schaaf, president of US Digital Investment for Omnicom Media Group told Reuters.

Pivotal Research Group analyst Brian Wieser said in a note: "The news reflects positive business momentum for Twitter and the fact that Twitter can sustain its revenue growth independently of growth in numbers of users given Twitter's uniqueness as a communications medium for marketers."

Earlier in the month, New York-based Omnicom and Paris-based Publicis terminated their proposed merger, citing "difficulties in completing the transaction within a reasonable time-frame."

In March, Facebook-owned Instagram inked an ad deal with Omnicom and the deal is reportedly worth some $100m.

Twitter acquired MoPub in September 2013 for $350m in stock.

Earlier in 2013, Twitter struck a multi-year deal with media agency Starcom Media Vest Group valued at hundreds of millions of dollars.