ABB's main constraint is its high valuation, Barclays analysts say in a research note. The Swiss industrial-technology company has a strong operational track record and tends to exceed expectations, which has afforded it an elevated valuation, the analysts say. This increases the downside risk should expected earnings fail to materialize, they say. Future share performance may increasingly depend on how effectively management deploys its significant balance sheet capacity, they add. The company recently signaled that it had up to $18 billion of available capital, without the need to adjust existing buyback, dividend or capital expenditure plans. The success of deploying this capital will likely determine how the company's valuation evolves moving forward, the analysts add. Shares trade broadly flat at 84.68 Swiss francs. (nina.kienle@wsj.com)